OBJECTIVETo observe the expressions of tumor necrosis factor a (TNF-alpha) and matrix metalloproteinase (MMP-9) in serum and matrix metalloproteinase 1 (MMP-1) mRNA in the bone tissue in chronic obstructive pulmonary disease (COPD) patients of cold dryness syndrome (CDS) in northwest China, thus providing reference for wholism treating COPD of CDS.

METHODSTwenty-one male Wistar rats were randomly divided into three groups, i.e., the normal control group, the COPD model group, and the COPD of CDS group, 7 in each group. The COPD model was established by dripping porcine pancreatic elastase (PEE) in trachea combination with cigarette smoking, and the COPD of CDS model was also set up by dripping PEE in trachea in combination with cigarette smoking and cold-dry environmental stress. Serum contents of TNF-alpha and MMP-9 were determined using ELISA. The MMP-1 mRNA expression in rats' bone tissue was detected using fluorescent quantitative PCR.

RESULTSCompared with the normal control group, the serum MMP-9 level obviously increased in the COPD of CDS group (P < 0.05). The MMP-1 mRNA expression level in the bone tissue of the COPD of CDS group and the COPD model group also obviously increased (P < 0.01, P < 0.05). The MMP-1 mRNA expression level was obviously higher in the COPD of CDS group than in the COPD model group (P < 0.01). There was no statistical difference in the serum TNF-alpha level among the three groups (P > 0.05).

CONCLUSIONCDS could increase the serum MMP-9 level and the MMP-1 mRNA expression in the bone tissue, which might be one of reasons for the fact that cold and dry environment causes more bone resorption and bone degradation in COPD.